Sydney Hunter Illawarra Forecast by Steve Shearer (issued Wed May 1st)

Features of the Forecast (tl;dr)

• Slow moving high now brings S-SE winds through the working week and into the weekend
• Scrappy S swells continue Thurs at modest levels
• Longer period S swells build in Fri PM, extending into Sat
• Trough may develop Sun into Mon bringing SE-E/SE winds
• Surf potential next week depends on evolution of trough, possibly sizey SE-E/SE swells - check back Fri for latest revisions 

Recap

Not much to get excited about since Mon wth S’ly winds establishing yesterday and underwhelming S swell in the 2-3ft range. A few semi-clean options around this morning with a morning SW breeze, mostly north of the Harbour, and S swell in the 3ft range, bigger and more onshore on the Hunter. All in all, not a very enticing day for surfing.

Raggedy S swell with winds already getting up

This week (May 1-May3)

A monster high (1042hPa) is slowly inching east well south of the Bight, with s S-SE flow anchored along the entire Eastern Seaboard. Troughs off the North Coast and inland will add instability to the onshore flow. A storm force polar low is better aimed at Pacific targets but we’ll still see some long period S groundswell from it this weekend, with the proviso that S’ly winds will remain persistent.

Not much change to the short run outlook. Mod S-SE winds with just a brief window of SW breezes likely north of the Harbour. Short range S/SE swell and sideband energy from a poorly aligned fetch on the eastern side of the Tasman will supply more 2-3ft S quadrant swell but keep expectations hosed down for quality.

Same again for Fri as far as winds go. Early birds will find the best of a bad lot. We may see a slight relaxation of the ridge later in the day leading to a slight lay down in windspeeds but it’s doubtful it will provide much in the way of an improvement in  quality. We will see a stronger S swell signal through as longer period swell trains fill in from late morning, pushing into the 3-4ft (occ bigger) range at S facing beaches. They’ll be wind affected so expect much smaller surf at protected spots.

This weekend (May4-5)

A strong but flukey signal of S’ly to S/SE’ly groundswell on offer for Sat with swell periods up in the 16 second band will provide some inconsistent 3-5ft surf at S facing beaches, grading smaller into more protected spots. Winds will remain S-SE, with some uncertainty depending on a troughy area north of the Hunter. Best to keep expectations low and we’ll see how winds look Fri. Best case scenario is pressure gradients easing enough for a more widespread SW land breeze which could clean up some of the S-SE bump. 

Onshore winds are modelled to increase on Sun as high pressure approaches Tasmania and reinforces the ridge possibly exacerbated by a trough in the Tasman. Models have consistently suggested then backed down off these troughy areas deepening into a low in the Tasman and that seems to be the theme for this week as well with a coastal trough now looking likely. That would suggest widespread onshore winds and rain for Sun with easing S swells.

Next week (May 6 onwards)

Models are still struggling to resolve the synoptic pattern for next week , although we have some degree of confidence that we’ll see onshore SE-E/SE winds Mon and into Tubes as high pressure slowly (and finally!) moves into the Tasman. 

With a widespread E-SE wind field in the Tasman at a minimum we’ll see moderate amounts of E/SE-E swell through the first half of next week.

By mid week we may see a trough form off the Central or MNC, possibly bringing an offshore flow to the f/cast region by Wed. 

GFS is suggesting a large low pressure system E of the North Island with a possible swell producing fetch off the West Coast down to Cook Strait mid next week. There's poor model agreement on this but we'll mention it now and report back Fri.

The location of the long wave trough suggests more swell aimed at Pacific targets with glancing blows from long period S-S/SE swells likely later next week.

In short, nothing concrete on the menu but we’ll take another look at it on Fri.
Seeya then!